#include "graphics/shader/recompiler/ir/passes/ResourceTracking.h"

#include "common/assert.h"
#include "graphics/shader/recompiler/ir/ShaderIR.h"
#include "graphics/shader/recompiler/ir/passes/SrtWalker.h"

#include <algorithm>
#include <fmt/format.h>
#include <span>
#include <utility>

namespace Libs::Graphics::ShaderRecompiler::IR {
namespace {

constexpr uint32_t SamplerBorderClampMask    = (1u << 2u) | (1u << 5u) | (1u << 8u);
constexpr uint32_t SamplerDword3ReservedMask = 0x3ffff000u;

uint32_t PossibleU32Bits(Value value) {
	value = value.Resolve();
	if (value.IsImmediate()) {
		return value.GetType() == Type::U32 ? value.U32() : UINT32_MAX;
	}
	const auto* inst = value.TryInstruction();
	if (inst == nullptr) {
		return UINT32_MAX;
	}
	switch (inst->GetOpcode()) {
		case ValueOpcode::BitwiseAnd32:
			return PossibleU32Bits(inst->Arg(0)) & PossibleU32Bits(inst->Arg(1));
		case ValueOpcode::BitwiseOr32:
			return PossibleU32Bits(inst->Arg(0)) | PossibleU32Bits(inst->Arg(1));
		case ValueOpcode::ShiftLeftLogical32: {
			const auto shift = inst->Arg(1).Resolve();
			return shift.IsImmediate() && shift.GetType() == Type::U32
			           ? PossibleU32Bits(inst->Arg(0)) << (shift.U32() & 31u)
			           : UINT32_MAX;
		}
		default: return UINT32_MAX;
	}
}

Value CanonicalizeSampleAdjustDword3(Value value) {
	for (;;) {
		value            = value.Resolve();
		const auto* inst = value.TryInstruction();
		if (inst == nullptr || inst->GetOpcode() != ValueOpcode::BitwiseOr32) {
			return value;
		}
		const auto left           = inst->Arg(0).Resolve();
		const auto right          = inst->Arg(1).Resolve();
		const bool left_reserved  = (PossibleU32Bits(left) & ~SamplerDword3ReservedMask) == 0;
		const bool right_reserved = (PossibleU32Bits(right) & ~SamplerDword3ReservedMask) == 0;
		if (left_reserved && right_reserved) {
			return Value(0u);
		}
		if (left_reserved) {
			value = right;
		} else if (right_reserved) {
			value = left;
		} else {
			return value;
		}
	}
}

const char* StageName(ShaderType stage) {
	switch (stage) {
		case ShaderType::Vertex: return "vertex";
		case ShaderType::Pixel: return "pixel";
		case ShaderType::Fetch: return "fetch";
		case ShaderType::Compute: return "compute";
		default: return "unknown";
	}
}

uint32_t ByteExtent(const MemoryInfo& memory) {
	const auto bytes = std::max((memory.data_bits + 7u) / 8u, 1u);
	const auto count = std::max(memory.data_dwords, 1u);
	const auto end   = static_cast<uint64_t>(memory.offset) + static_cast<uint64_t>(bytes) * count;
	return end > UINT32_MAX ? UINT32_MAX : static_cast<uint32_t>(end);
}

class Tracker {
public:
	explicit Tracker(Program& program): m_program(program), m_info(program.info) {
		m_info.buffers.clear();
		m_info.images.clear();
		m_info.samplers.clear();
		m_info.sampled_pairs.clear();
		m_info.uses_dma = false;
		m_shader_writes = HasShaderMemoryWrites(program);
	}

	void Run() {
		if (m_program.resource_tracking_complete) {
			Fail(0, "resources already tracked");
		}
		if (!m_program.srt_plan_complete) {
			Fail(0, "SRT plan is not ready");
		}
		PlanIndirectImages();
		for (auto* block: m_program.blocks) {
			for (auto& inst: *block) {
				Collect(inst);
			}
		}
		LinkImageAliases();
		for (const auto& patch: m_handle_patches) {
			patch.handle->SetFlags<uint32_t>(patch.resource);
		}
		for (const auto& patch: m_memory_patches) {
			auto& memory    = m_program.memory_info[patch.index];
			memory.resource = patch.resource;
			if (patch.has_sampler) {
				memory.sampler = patch.sampler;
			}
		}
		for (const auto& plan: m_indirect_images) {
			plan.handle->SetArg(0, plan.key);
			for (uint32_t dword = 0; dword < 4u; dword++) {
				plan.handle->SetArg(dword + 1u, plan.roots[dword + 4u]);
			}
			for (uint32_t dword = 5u; dword < plan.roots.size(); dword++) {
				plan.handle->SetArg(dword, plan.key);
			}
			for (const auto index: plan.memory) {
				m_program.memory_info[index].planning_only = true;
			}
		}
		std::erase_if(m_program.dynamic_reads, [&](Value value) {
			const auto* inst = value.Resolve().TryInstruction();
			return std::any_of(m_indirect_images.begin(), m_indirect_images.end(),
			                   [&](const IndirectImagePlan& plan) {
				return std::ranges::find(plan.reads, inst) != plan.reads.end();
			});
		});
		m_program.descriptor_sources         = std::move(m_sources);
		m_program.info                       = std::move(m_info);
		m_program.resource_tracking_complete = true;
	}

private:
	struct HandlePatch {
		Inst*    handle   = nullptr;
		uint32_t resource = 0;
	};

	struct MemoryPatch {
		uint32_t index       = 0;
		uint32_t resource    = 0;
		uint32_t sampler     = 0;
		bool     has_sampler = false;
	};

	struct IndirectImagePlan {
		Inst*                      handle = nullptr;
		uint32_t                   source = 0;
		Value                      key;
		std::array<Value, 8>       roots {};
		std::array<uint32_t, 8>    memory {};
		std::array<const Inst*, 8> reads {};
	};

	[[noreturn]] void Fail(uint32_t pc, const std::string& reason) const {
		const auto message =
		    fmt::format("shader resource tracking: hash=0x{:016x} stage={} pc=0x{:08x} {}",
		                m_program.shader_hash, StageName(m_program.stage), pc, reason);
		EXIT("%s", message.c_str());
		std::abort();
	}

	Value LowerDescriptorPhi(Value value) {
		value           = value.Resolve();
		const auto* phi = value.TryInstruction();
		if (m_shader_writes || phi == nullptr || phi->GetOpcode() != ValueOpcode::Phi ||
		    phi->NumArgs() != 2u || phi->NumPhiBlocks() != 2u || phi->GetType() != Type::U32 ||
		    m_program.blocks.size() != m_program.block_info.size()) {
			return value;
		}
		for (const auto& [original, selected]: m_descriptor_selections) {
			if (original == phi) {
				return selected;
			}
		}
		const auto* merge  = phi->Parent();
		const auto* branch = phi->PhiBlock(0);
		if (merge == nullptr || branch == nullptr || phi->PhiBlock(1) == nullptr ||
		    branch == phi->PhiBlock(1)) {
			return value;
		}
		if (branch->ImmSuccessors().size() != 2u) {
			if (branch->ImmPredecessors().size() != 1u) {
				return value;
			}
			branch = branch->ImmPredecessors()[0];
		}
		if (branch == merge || branch->ImmSuccessors().size() != 2u) {
			return value;
		}
		std::array<uint32_t, 2> target_ids;
		for (uint32_t arm = 0; arm < 2; arm++) {
			const auto* incoming = phi->PhiBlock(arm);
			if (incoming == merge ||
			    (incoming != branch &&
			     (incoming->ImmPredecessors().size() != 1u ||
			      incoming->ImmPredecessors()[0] != branch ||
			      incoming->ImmSuccessors().size() != 1u ||
			      incoming->ImmSuccessors()[0] != merge))) {
				return value;
			}
			const auto* target = incoming == branch ? merge : incoming;
			const auto  it     = std::ranges::find(m_program.blocks, target);
			if (it == m_program.blocks.end()) {
				return value;
			}
			target_ids[arm] = m_program.block_info[it - m_program.blocks.begin()].id;
		}
		const auto branch_it = std::ranges::find(m_program.blocks, branch);
		if (branch_it == m_program.blocks.end()) {
			return value;
		}
		const auto& info = m_program.block_info[branch_it - m_program.blocks.begin()];
		const auto& term = info.terminator;
		if (term.kind != CFG::TerminatorKind::ConditionalBranch ||
		    !((term.true_block == target_ids[0] && term.false_block == target_ids[1]) ||
		      (term.false_block == target_ids[0] && term.true_block == target_ids[1])) ||
		    !ValidateRuntimeValue(m_program, info.condition, RuntimeValueType::Integer) ||
		    !ValidateRuntimeValue(m_program, phi->Arg(0)) ||
		    !ValidateRuntimeValue(m_program, phi->Arg(1))) {
			return value;
		}
		// Retain a host expression; replacing the GPU Phi would break SSA dominance.
		const auto true_arg = term.true_block == target_ids[0] ? 0u : 1u;
		auto&      selected = m_program.value_storage.emplace_back(ValueOpcode::SelectU32);
		selected.SetArg(0, info.condition);
		selected.SetArg(1, phi->Arg(true_arg));
		selected.SetArg(2, phi->Arg(true_arg ^ 1u));
		m_descriptor_selections.emplace_back(phi, Value(&selected));
		return Value(&selected);
	}

	void MakeSource(const Inst& handle, uint32_t width, bool sampler, bool sample_adjust,
	                DescriptorSource& descriptor, uint32_t pc) {
		if (handle.NumArgs() != width) {
			Fail(pc, fmt::format("{} has {} descriptor dwords, expected {}",
			                     ValueOpcodeName(handle.GetOpcode()), handle.NumArgs(), width));
		}
		descriptor.dword_count = width;
		for (uint32_t i = 0; i < width; i++) {
			descriptor.dwords[i] = LowerDescriptorPhi(handle.Arg(i));
		}
		if (sample_adjust) {
			descriptor.dwords[3] = CanonicalizeSampleAdjustDword3(descriptor.dwords[3]);
		}
		const auto dword0 = descriptor.dwords[0].Resolve();
		if (sampler && dword0.IsImmediate() && dword0.GetType() == Type::U32 &&
		    (dword0.U32() & SamplerBorderClampMask) == 0) {
			// Border color and its table index are unused unless a clamp axis selects border mode.
			descriptor.dwords[3] = Value(0u);
		}
	}

	bool ValidateSource(const DescriptorSource& descriptor, uint32_t& bad_dword) const {
		for (uint32_t i = 0; i < descriptor.dword_count; i++) {
			bad_dword = i;
			if (descriptor.dwords[i].Resolve().GetType() != Type::U32) {
				return false;
			}
			if (!ValidateRuntimeValue(m_program, descriptor.dwords[i])) {
				return false;
			}
		}
		return true;
	}

	uint32_t InternSource(const DescriptorSource& descriptor) {
		for (uint32_t candidate = 0; candidate < m_sources.size(); candidate++) {
			const auto& current = m_sources[candidate];
			if (current.dword_count != descriptor.dword_count ||
			    current.indirect_image != descriptor.indirect_image) {
				continue;
			}
			bool same = true;
			for (uint32_t i = 0; i < descriptor.dword_count; i++) {
				same = same && EquivalentValue(m_program, current.dwords[i], descriptor.dwords[i]);
			}
			if (same) {
				return candidate;
			}
		}
		m_sources.push_back(descriptor);
		return static_cast<uint32_t>(m_sources.size() - 1);
	}

	static bool ImmediateU32(Value value, uint32_t& result) {
		value = value.Resolve();
		if (!value.IsImmediate() || value.GetType() != Type::U32) {
			return false;
		}
		result = value.U32();
		return true;
	}

	static bool UsesOnly(const Inst& value, std::span<const Inst* const> users) {
		return !value.Uses().empty() && std::ranges::all_of(value.Uses(), [&](const Use& use) {
			return std::ranges::find(users, use.user) != users.end();
		});
	}

	const MemoryInfo* ScalarReadMemory(const Inst& read, uint32_t& index) const {
		if (read.GetOpcode() != ValueOpcode::ReadConstBuffer || read.NumArgs() != 2u) {
			return nullptr;
		}
		index = read.Flags<MemoryFlags>().index;
		if (index >= m_program.memory_info.size()) {
			return nullptr;
		}
		const auto& memory = m_program.memory_info[index];
		return memory.kind == ResourceKind::ScalarBuffer && memory.data_bits == 32u &&
		               memory.data_dwords == 1u
		           ? &memory
		           : nullptr;
	}

	bool MemoryIndexBelongsTo(uint32_t index, const Inst& owner) const {
		for (const auto* block: m_program.blocks) {
			for (const auto& inst: *block) {
				const auto op = inst.GetOpcode();
				if ((BufferAccessOf(op) == BufferAccess::None &&
				     AddressOpcodeInfoOf(op).access == AddressAccess::None &&
				     ImageOpcodeInfoOf(op).access == ImageAccess::None) ||
				    &inst == &owner) {
					continue;
				}
				if (inst.Flags<MemoryFlags>().index == index) {
					return false;
				}
			}
		}
		return true;
	}

	bool MakeRuntimeBufferSource(const Inst& handle, uint32_t pc, uint32_t& source,
	                             DescriptorSource& descriptor) {
		if (handle.GetOpcode() != ValueOpcode::GetBufferResource) {
			return false;
		}
		MakeSource(handle, 4u, false, false, descriptor, pc);
		uint32_t bad_dword = 0;
		if (!ValidateSource(descriptor, bad_dword)) {
			return false;
		}
		source = InternSource(descriptor);
		return true;
	}

	bool MatchMaterialOffset(Value value, Value& selector, uint32_t& stride,
	                         uint32_t& offset) const {
		value           = value.Resolve();
		offset          = 0;
		auto* candidate = value.TryInstruction();
		if (candidate != nullptr && candidate->GetOpcode() == ValueOpcode::IAdd32 &&
		    candidate->NumArgs() == 2u) {
			uint32_t immediate = 0;
			if (ImmediateU32(candidate->Arg(0), immediate)) {
				value = candidate->Arg(1).Resolve();
			} else if (ImmediateU32(candidate->Arg(1), immediate)) {
				value = candidate->Arg(0).Resolve();
			} else {
				return false;
			}
			offset = immediate;
		}
		const auto* multiply = value.TryInstruction();
		if (multiply == nullptr || multiply->GetOpcode() != ValueOpcode::IMul32 ||
		    multiply->NumArgs() != 2u) {
			return false;
		}
		if (ImmediateU32(multiply->Arg(0), stride)) {
			selector = multiply->Arg(1).Resolve();
		} else if (ImmediateU32(multiply->Arg(1), stride)) {
			selector = multiply->Arg(0).Resolve();
		} else {
			return false;
		}
		const auto* selector_inst = selector.TryInstruction();
		return stride != 0u && selector_inst != nullptr &&
		       selector_inst->GetOpcode() == ValueOpcode::ReadFirstLane;
	}

	bool TryMakeIndirectImage(Inst& handle, uint32_t pc, IndirectImagePlan& plan) {
		if (handle.GetOpcode() != ValueOpcode::GetImageResource || handle.NumArgs() != 8u) {
			return false;
		}

		std::array<Inst*, 8> heap_reads {};
		Inst*                heap_handle = nullptr;
		Value                heap_offset;
		for (uint32_t dword = 0; dword < heap_reads.size(); dword++) {
			heap_reads[dword] = handle.Arg(dword).Resolve().TryInstruction();
			if (heap_reads[dword] == nullptr) {
				return false;
			}
			uint32_t    memory_index = 0;
			const auto* memory       = ScalarReadMemory(*heap_reads[dword], memory_index);
			if (memory == nullptr || memory->offset != dword * sizeof(uint32_t) ||
			    !MemoryIndexBelongsTo(memory_index, *heap_reads[dword])) {
				return false;
			}
			auto* current_handle = heap_reads[dword]->Arg(0).Resolve().TryInstruction();
			if (current_handle == nullptr ||
			    (heap_handle != nullptr && current_handle != heap_handle)) {
				return false;
			}
			heap_handle = current_handle;
			if (dword == 0u) {
				heap_offset = heap_reads[dword]->Arg(1).Resolve();
			} else if (!EquivalentValue(m_program, heap_offset, heap_reads[dword]->Arg(1))) {
				return false;
			}
			plan.memory[dword] = memory_index;
			plan.reads[dword]  = heap_reads[dword];
		}

		const auto* shift        = heap_offset.TryInstruction();
		uint32_t    shift_amount = 0;
		if (shift == nullptr || shift->GetOpcode() != ValueOpcode::ShiftLeftLogical32 ||
		    shift->NumArgs() != 2u || !ImmediateU32(shift->Arg(1), shift_amount) ||
		    shift_amount != 5u) {
			return false;
		}
		auto* material_read = shift->Arg(0).Resolve().TryInstruction();
		if (material_read == nullptr) {
			return false;
		}
		uint32_t    material_memory_index = 0;
		const auto* material_memory       = ScalarReadMemory(*material_read, material_memory_index);
		if (material_memory == nullptr || material_memory->offset != 0u ||
		    !MemoryIndexBelongsTo(material_memory_index, *material_read)) {
			return false;
		}
		auto* material_handle = material_read->Arg(0).Resolve().TryInstruction();
		if (material_handle == nullptr) {
			return false;
		}

		Value    selector;
		uint32_t selector_stride = 0;
		uint32_t selector_offset = 0;
		if (!MatchMaterialOffset(material_read->Arg(1), selector, selector_stride,
		                         selector_offset)) {
			return false;
		}

		const std::array<const Inst*, 1> material_users {shift};
		std::array<const Inst*, 8>       heap_users {};
		std::copy(heap_reads.begin(), heap_reads.end(), heap_users.begin());
		const std::array<const Inst*, 1> image_users {&handle};
		if (!UsesOnly(*material_read, material_users) || !UsesOnly(*shift, heap_users)) {
			return false;
		}
		for (const auto* read: heap_reads) {
			if (!UsesOnly(*read, image_users)) {
				return false;
			}
		}

		DescriptorSource material_source;
		DescriptorSource heap_source;
		uint32_t         material_source_index = 0;
		uint32_t         heap_source_index     = 0;
		if (!MakeRuntimeBufferSource(*material_handle, pc, material_source_index,
		                             material_source) ||
		    !MakeRuntimeBufferSource(*heap_handle, pc, heap_source_index, heap_source)) {
			return false;
		}

		DescriptorSource image_source;
		image_source.dword_count = 8u;
		std::copy(material_source.dwords.begin(), material_source.dwords.begin() + 4u,
		          image_source.dwords.begin());
		std::copy(heap_source.dwords.begin(), heap_source.dwords.begin() + 4u,
		          image_source.dwords.begin() + 4u);
		image_source.indirect_image = DescriptorSource::IndirectImage {
		    material_source_index, heap_source_index, selector_stride, selector_offset, 0u};

		plan.handle = &handle;
		plan.source = InternSource(image_source);
		plan.key    = Value(material_read);
		plan.roots  = image_source.dwords;
		return true;
	}

	const IndirectImagePlan* FindIndirectImage(const Inst& handle) const {
		const auto found =
		    std::find_if(m_indirect_images.begin(), m_indirect_images.end(),
		                 [&](const IndirectImagePlan& plan) {
			    return plan.handle == &handle;
		    });
		return found == m_indirect_images.end() ? nullptr : &*found;
	}

	bool IsIndirectPlanningMemory(uint32_t index) const {
		return std::any_of(m_indirect_images.begin(), m_indirect_images.end(),
		                   [&](const IndirectImagePlan& plan) {
			return std::ranges::find(plan.memory, index) != plan.memory.end();
		});
	}

	void PlanIndirectImages() {
		for (auto* block: m_program.blocks) {
			for (auto& inst: *block) {
				if (ImageOpcodeInfoOf(inst.GetOpcode()).access == ImageAccess::None ||
				    inst.NumArgs() == 0u) {
					continue;
				}
				auto* handle = inst.Arg(0).Resolve().TryInstruction();
				if (handle == nullptr || FindIndirectImage(*handle) != nullptr) {
					continue;
				}
				IndirectImagePlan plan;
				if (TryMakeIndirectImage(*handle, inst.Flags<MemoryFlags>().pc, plan)) {
					m_indirect_images.push_back(std::move(plan));
				}
			}
		}
	}

	bool GetHandle(Value value, ValueOpcode expected, uint32_t width, uint32_t pc, Inst*& handle,
	               uint32_t& source, bool sampler = false, bool sample_adjust = false) {
		handle = value.Resolve().TryInstruction();
		if (handle == nullptr || handle->GetOpcode() != expected) {
			Fail(pc, fmt::format("memory operation requires {}", ValueOpcodeName(expected)));
		}
		DescriptorSource descriptor;
		MakeSource(*handle, width, sampler, sample_adjust, descriptor, pc);
		uint32_t bad_dword = 0;
		if (expected == ValueOpcode::GetImageResource) {
			for (; bad_dword < descriptor.dword_count; bad_dword++) {
				const auto* value = descriptor.dwords[bad_dword].Resolve().TryInstruction();
				if (value != nullptr && value->GetOpcode() == ValueOpcode::ReadConstBuffer) {
					Fail(pc, fmt::format("{} dword {} is not a valid runtime value",
					                     ValueOpcodeName(expected), bad_dword));
				}
			}
			bad_dword = 0;
		}
		if (!ValidateSource(descriptor, bad_dword)) {
			if (expected == ValueOpcode::GetBufferResource &&
			    std::all_of(descriptor.dwords.begin(), descriptor.dwords.begin() + width,
			                [](Value word) { return word.Resolve().GetType() == Type::U32; })) {
				return false;
			}
			Fail(pc, fmt::format("{} dword {} is not a valid runtime value",
			                     ValueOpcodeName(expected), bad_dword));
		}
		source = InternSource(descriptor);
		return true;
	}

	void ValidateAddressHandle(Value value, uint32_t pc) const {
		const auto* handle = value.Resolve().TryInstruction();
		if (handle == nullptr || handle->GetOpcode() != ValueOpcode::GetAddressResource) {
			Fail(pc, "address operation requires GetAddressResource");
		}
		if (handle->NumArgs() != 2) {
			Fail(pc, "GetAddressResource must have two address dwords");
		}
	}

	uint32_t AddBuffer(uint32_t source, const MemoryInfo& memory, ValueOpcode op, uint32_t pc) {
		for (uint32_t i = 0; i < m_info.buffers.size(); i++) {
			if (m_info.buffers[i].source == source) {
				Merge(m_info.buffers[i], memory, op, pc);
				return i;
			}
		}
		if (m_info.buffers.size() >= ShaderInfo::MaxBuffers) {
			return UINT32_MAX;
		}
		BufferResource resource;
		resource.source       = source;
		resource.first_use_pc = pc;
		Merge(resource, memory, op, pc);
		m_info.buffers.push_back(resource);
		return static_cast<uint32_t>(m_info.buffers.size() - 1);
	}

	static void Merge(BufferResource& resource, const MemoryInfo& memory, ValueOpcode op,
	                  uint32_t pc) {
		const auto access        = BufferAccessOf(op);
		const bool atomic        = access == BufferAccess::Atomic;
		const bool write         = access == BufferAccess::Write || atomic;
		resource.first_use_pc    = std::min(resource.first_use_pc, pc);
		resource.max_byte_extent = std::max(resource.max_byte_extent, ByteExtent(memory));
		resource.read            = resource.read || !write || atomic;
		resource.written         = resource.written || write;
		resource.atomic          = resource.atomic || atomic;
		resource.formatted       = resource.formatted || memory.formatted;
		resource.scalar          = resource.scalar || op == ValueOpcode::ReadConstBuffer ||
		                           memory.kind == ResourceKind::ScalarBuffer;
	}

	uint32_t AddImage(uint32_t source, const MemoryInfo& memory, ValueOpcode op, uint32_t pc) {
		const auto resource_class = ImageOpcodeInfoOf(op).resource_class;
		const auto mip   = resource_class == ImageResourceClass::Storage && memory.image_has_mip
		                       ? ImageMipMode::DynamicStorage
		                       : ImageMipMode::None;
		const bool depth = (memory.image_sample_flags & Decoder::ImageSampleFlagCompare) != 0;
		for (uint32_t i = 0; i < m_info.images.size(); i++) {
			auto& image = m_info.images[i];
			if (image.source == source && image.resource_class == resource_class &&
			    image.dimension == memory.image_dimension && image.mip_mode == mip &&
			    image.depth_compare == depth && image.r128 == memory.image_r128) {
				Merge(image, op, pc);
				return i;
			}
		}
		if (m_info.images.size() >= ShaderInfo::MaxImages) {
			return UINT32_MAX;
		}
		ImageResource image;
		image.source         = source;
		image.first_use_pc   = pc;
		image.resource_class = resource_class;
		image.dimension      = memory.image_dimension;
		image.mip_mode       = mip;
		image.depth_compare  = depth;
		image.r128           = memory.image_r128;
		Merge(image, op, pc);
		m_info.images.push_back(image);
		return static_cast<uint32_t>(m_info.images.size() - 1);
	}

	static void Merge(ImageResource& image, ValueOpcode op, uint32_t pc) {
		const auto access  = ImageOpcodeInfoOf(op).access;
		const bool atomic  = access == ImageAccess::Atomic;
		const bool write   = access == ImageAccess::Write || atomic;
		image.first_use_pc = std::min(image.first_use_pc, pc);
		image.read         = image.read || !write || atomic;
		image.written      = image.written || write;
		image.atomic       = image.atomic || atomic;
	}

	uint32_t AddSampler(uint32_t source, uint32_t pc) {
		for (uint32_t i = 0; i < m_info.samplers.size(); i++) {
			if (m_info.samplers[i].source == source) {
				m_info.samplers[i].first_use_pc = std::min(m_info.samplers[i].first_use_pc, pc);
				return i;
			}
		}
		if (m_info.samplers.size() >= ShaderInfo::MaxSamplers) {
			return UINT32_MAX;
		}
		m_info.samplers.push_back({source, pc});
		return static_cast<uint32_t>(m_info.samplers.size() - 1);
	}

	void AddSampledPair(uint32_t image, uint32_t sampler, uint32_t pc) {
		for (auto& pair: m_info.sampled_pairs) {
			if (pair.image == image && pair.sampler == sampler) {
				pair.first_use_pc = std::min(pair.first_use_pc, pc);
				return;
			}
		}
		if (m_info.sampled_pairs.size() >= ShaderInfo::MaxSampledPairs) {
			Fail(pc, "sampled image/sampler pair limit exceeded");
		}
		m_info.sampled_pairs.push_back({image, sampler, pc});
	}

	void AddHandlePatch(Inst* handle, uint32_t resource, uint32_t pc) {
		for (const auto& patch: m_handle_patches) {
			if (patch.handle == handle) {
				if (patch.resource != resource) {
					Fail(pc, fmt::format("{} is reused with incompatible resource classes",
					                     ValueOpcodeName(handle->GetOpcode())));
				}
				return;
			}
		}
		m_handle_patches.push_back({handle, resource});
	}

	void AddMemoryPatch(uint32_t index, uint32_t resource, uint32_t sampler, bool has_sampler,
	                    uint32_t pc) {
		for (auto& patch: m_memory_patches) {
			if (patch.index != index) {
				continue;
			}
			if (patch.resource != resource ||
			    (has_sampler && patch.has_sampler && patch.sampler != sampler)) {
				Fail(pc, "memory metadata is reused with incompatible resources");
			}
			if (has_sampler) {
				patch.sampler     = sampler;
				patch.has_sampler = true;
			}
			return;
		}
		m_memory_patches.push_back({index, resource, sampler, has_sampler});
	}

	void Collect(Inst& inst) {
		const auto op           = inst.GetOpcode();
		const auto buffer       = BufferAccessOf(op);
		const auto address_info = AddressOpcodeInfoOf(op);
		const auto image_info   = ImageOpcodeInfoOf(op);
		if (buffer == BufferAccess::None && address_info.access == AddressAccess::None &&
		    image_info.access == ImageAccess::None) {
			return;
		}
		const auto flags = inst.Flags<MemoryFlags>();
		if (flags.index >= m_program.memory_info.size()) {
			Fail(flags.pc, fmt::format("memory metadata index {} is out of range", flags.index));
		}
		if (inst.NumArgs() == 0) {
			Fail(flags.pc, "memory operation has no resource handle");
		}
		const auto& memory = m_program.memory_info[flags.index];
		if (memory.planning_only || IsIndirectPlanningMemory(flags.index)) {
			return;
		}
		Inst*    handle   = nullptr;
		uint32_t source   = 0;
		uint32_t resource = 0;

		if (buffer != BufferAccess::None) {
			if (!GetHandle(inst.Arg(0), ValueOpcode::GetBufferResource, 4, flags.pc, handle,
			               source)) {
				if (memory.kind != ResourceKind::Buffer || memory.formatted || memory.typed ||
				    (op != ValueOpcode::LoadBufferU32x2 && op != ValueOpcode::LoadBufferU32x4)) {
					Fail(flags.pc,
					     "buffer descriptor is not a valid runtime value; GPU-selected access "
					     "requires a raw DWORD x2/x4 load");
				}
				m_program.memory_info[flags.index].kind = ResourceKind::IndirectBuffer;
				m_info.uses_dma                         = true;
				return;
			}
			resource = AddBuffer(source, memory, op, flags.pc);
			if (resource == UINT32_MAX) {
				Fail(flags.pc, "buffer resource limit exceeded");
			}
			AddHandlePatch(handle, resource, flags.pc);
			AddMemoryPatch(flags.index, resource, 0, false, flags.pc);
			return;
		}
		if (address_info.access != AddressAccess::None) {
			if (!IsAddressResourceKind(memory.kind)) {
				Fail(flags.pc, "address operation has invalid resource kind");
			}
			if (memory.kind == ResourceKind::Scratch) {
				handle = inst.Arg(0).Resolve().TryInstruction();
				if (handle == nullptr || handle->GetOpcode() != ValueOpcode::GetScratchResource ||
				    handle->NumArgs() != 0) {
					Fail(flags.pc, "scratch operation requires GetScratchResource");
				}
				if (m_program.scratch_dwords == 0) {
					Fail(flags.pc, "scratch operation requires a nonzero AGC per-thread size");
				}
				return;
			}
			ValidateAddressHandle(inst.Arg(0), flags.pc);
			m_info.uses_dma = true;
			return;
		}

		if (memory.kind != ResourceKind::Image ||
		    image_info.resource_class == ImageResourceClass::None) {
			Fail(flags.pc, "image operation has invalid resource kind");
		}
		handle               = inst.Arg(0).Resolve().TryInstruction();
		const auto* indirect = handle != nullptr ? FindIndirectImage(*handle) : nullptr;
		if (indirect != nullptr) {
			source = indirect->source;
		} else {
			GetHandle(inst.Arg(0), ValueOpcode::GetImageResource, 8, flags.pc, handle, source);
		}
		resource = AddImage(source, memory, op, flags.pc);
		if (resource == UINT32_MAX) {
			Fail(flags.pc, "image resource limit exceeded");
		}
		AddHandlePatch(handle, resource, flags.pc);
		uint32_t sampler = 0;
		if (image_info.needs_sampler) {
			if (inst.NumArgs() < 2) {
				Fail(flags.pc, "sampled image operation has no sampler handle");
			}
			Inst*      sampler_handle = nullptr;
			uint32_t   sampler_source = 0;
			const bool sample_adjust =
			    (memory.image_sample_flags & Decoder::ImageSampleFlagAdjust) != 0;
			GetHandle(inst.Arg(1), ValueOpcode::GetSamplerResource, 4, flags.pc, sampler_handle,
			          sampler_source, true, sample_adjust);
			sampler = AddSampler(sampler_source, flags.pc);
			if (sampler == UINT32_MAX) {
				Fail(flags.pc, "sampler resource limit exceeded");
			}
			AddHandlePatch(sampler_handle, sampler, flags.pc);
			AddSampledPair(resource, sampler, flags.pc);
		}
		AddMemoryPatch(flags.index, resource, sampler, image_info.needs_sampler, flags.pc);
	}

	const DescriptorSource* Source(uint32_t source) const {
		return source < m_sources.size() ? &m_sources[source] : nullptr;
	}

	void LinkImageAliases() {
		for (auto& buffer: m_info.buffers) {
			const auto* buffer_source = Source(buffer.source);
			if (buffer_source == nullptr || buffer_source->dword_count != 4) {
				continue;
			}
			for (uint32_t image = 0; image < m_info.images.size(); image++) {
				const auto* image_source = Source(m_info.images[image].source);
				if (image_source == nullptr || image_source->dword_count != 8 ||
				    image_source->indirect_image.has_value()) {
					continue;
				}
				bool alias = true;
				for (uint32_t dword = 0; dword < 4; dword++) {
					alias = alias && EquivalentValue(m_program, buffer_source->dwords[dword],
					                                 image_source->dwords[dword]);
				}
				if (alias) {
					buffer.image_alias = image;
					break;
				}
			}
		}
	}

	Program&                                   m_program;
	ShaderInfo                                 m_info;
	std::vector<DescriptorSource>              m_sources;
	std::vector<HandlePatch>                   m_handle_patches;
	std::vector<MemoryPatch>                   m_memory_patches;
	std::vector<IndirectImagePlan>             m_indirect_images;
	std::vector<std::pair<const Inst*, Value>> m_descriptor_selections;
	bool                                       m_shader_writes = false;
};

} // namespace

void TrackResources(Program& program) {
	Tracker(program).Run();
}

} // namespace Libs::Graphics::ShaderRecompiler::IR